CN113895030A

CN113895030A - Sinking type 3D printer and 3D printing method

Info

Publication number: CN113895030A
Application number: CN202111287934.4A
Authority: CN
Inventors: 张佳新; 邢有道; 王振; 李柏松
Original assignee: Aidite Qinhuangdao Technology Co ltd
Current assignee: Aidite Qinhuangdao Technology Co ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2022-01-07
Also published as: EP4173804A1; US20230133696A1; US11951680B2

Abstract

The invention belongs to the technical field of 3D printers and discloses a sunken 3D printer and a 3D printing method. Wherein, formula 3D printer sinks includes main mesa, first straight line actuating mechanism, second straight line actuating mechanism, print platform and ray apparatus scraper subassembly. The main table top comprises a horizontal table top and a vertical table top which are vertically arranged, and a resin groove is formed in the horizontal table top; the first linear driving mechanism and the second linear driving mechanism are installed at two ends of the vertical table board, the first linear driving mechanism is used for driving the printing platform to move up and down, and the second linear driving mechanism is used for driving the optical machine scraper assembly to move up and down. This formula of sinking 3D printer prints the precision height, prints the model and at print platform top solidification shaping, does not exist and falls the board phenomenon, printable bigger, heavier 3D model. The 3D printing method uses the sinking type 3D printer, the printing precision is high, the efficiency is high, the printing thickness of each layer of the model is accurately controlled, and the printing cost is low.

Description

Sinking type 3D printer and 3D printing method

Technical Field

The invention relates to the technical field of 3D printers, in particular to a sinking type 3D printer and a 3D printing method.

Background

The resin tank of traditional photocuring 3D printer comprises resin tank frame, glass board, release film and compartment membrane, contains photocuring resin in the resin tank, and the ray apparatus is arranged in the below of resin tank, and print platform sets up the top in the resin tank. When 3D printing is carried out, the printing platform is made to descend to the bottom of a resin tank containing photocureable resin, a cross-sectional view of the three-dimensional model projected by the optical machine sequentially penetrates through the glass plate, the spacer film and the release film, and finally the three-dimensional model is irradiated on the resin in a gap between the release film and the printing platform, so that the resin in the gap between the release film and the printing platform is subjected to curing reaction and is cured into a shape of a projected image, and the thickness of the cured resin layer is the height of the gap between the printing platform and the release film. Then the printing platform begins to pull up, because the printing platform is a rigid structure and fine sand grains are attached to the printing platform, the adhesive force between the solidified resin layer and the printing platform is greater than the adhesive force between the solidified resin layer and the release film, and when the printing platform is pulled up, the solidified resin layer is attached to the printing platform and is peeled off from the release film. When the second layer is printed, the printing platform descends into the resin tank again, a certain gap is reserved between the printing platform and the release film in the resin tank, and the operation is repeated in a circulating mode until the model printing is completed.

For a traditional photocuring 3D printer, the release film is an elastic transparent film, and the elasticity is reduced after repeated use, so that the release film becomes loose and the printing precision is influenced; the optical machine is arranged below the resin tank, and when small particles are introduced into the resin tank or a small printing model is left in the resin tank, the release film or the glass plate is damaged due to continuous printing, so that the resin liquid in the tank flows out to the optical machine lens, and the lens is permanently damaged; the existence of the glass plate, the spacer film and the release film leads the light to be refracted for six times when reaching the resin curing surface, thus the printing precision is seriously reduced; and under the influence of the release force, the bonding force of the cured layer resin and the printing platform is smaller and smaller, and the model which is not printed is likely to fall off from the printing platform.

Disclosure of Invention

The invention aims to provide a sunken 3D printer and a 3D printing method, and aims to solve the problems that a model falls off a plate, the printing precision is low, and printing consumables need to be replaced regularly.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, a sink type 3D printer is provided, including:

the main table top comprises a horizontal table top and a vertical table top which are vertically arranged, and a resin groove is formed in the horizontal table top;

the first linear driving mechanism is arranged at one end, close to the horizontal table top, of the vertical table top, and a first output end of the first linear driving mechanism can move upwards or downwards along the vertical direction;

the second linear driving mechanism is arranged at the other end, far away from the horizontal table top, of the vertical table top, and a second output end of the second linear driving mechanism can move upwards or downwards along the vertical direction;

the printing platform is fixedly connected with the first output end and moves upwards or downwards along with the first output end;

ray apparatus scraper assembly, ray apparatus scraper assembly arranges in print platform top, ray apparatus scraper assembly includes:

the optical-mechanical mechanism comprises an optical-mechanical and an optical-mechanical mounting seat which are fixedly connected, and the optical-mechanical mounting seat is fixedly connected with the second output end and moves upwards or downwards along with the second output end;

scraper mechanism, scraper mechanism includes scraper motor, scrapes the axle and scraper, the scraper motor with ray apparatus mount pad fixed connection, the one end of scraping the axle with the output fixed connection of scraper motor, the other end of scraping the axle with scraper fixed connection, be provided with range finding sensor on the scraper, the scraper motor can drive fan-shaped motion is to the scraper.

Optionally, the first linear drive mechanism comprises:

two first screw rod mounting seats are arranged, and the two first screw rod mounting seats are arranged on the vertical table board at intervals along the same vertical direction;

the two ends of the first driving screw are rotationally connected with the two first screw mounting seats;

the output end of the first driving motor is fixedly connected with the first driving screw rod;

the first driving sliding block is in threaded connection with the first driving screw rod, and when the first driving motor is started, the first driving sliding block serves as the first output end of the first linear driving mechanism and can drive the printing platform to move upwards or downwards along the vertical direction.

Optionally, the printing platform comprises a platform bracket and a platform supporting plate, the first linear driving mechanism is installed on the back of the vertical table top, two strip-shaped through holes are formed in the vertical table top, two platform brackets are arranged, and the two platform brackets correspond to the two strip-shaped through holes one to one; one end of the platform bracket is fixedly connected with the platform supporting plate, and the other end of the platform bracket penetrates through the strip-shaped through hole to be fixedly connected with the first driving sliding block.

Optionally, the printing platform further comprises a platform bracket connecting block, and two ends of the platform bracket connecting block are fixedly connected with the two platform brackets.

Optionally, a linear bearing is arranged on the platform bracket connecting block, and the scraper shaft penetrates through the linear bearing.

Optionally, the second linear drive mechanism comprises:

two second screw rod mounting seats are arranged, and the two second screw rod mounting seats are arranged on the vertical table board at intervals along the same vertical direction;

two ends of the second driving screw are rotatably connected with the two second screw mounting seats;

the output end of the second driving motor is fixedly connected with the second driving screw rod;

and the second driving sliding block is in threaded connection with the second driving screw rod, and when the second driving motor is started, the second driving sliding block is used as the second output end of the second linear driving mechanism and can drive the optical-mechanical mechanism and the scraper mechanism to move upwards or downwards along the vertical direction.

Optionally, the second linear driving mechanism further comprises two linear guide rails, the two linear guide rails are arranged on the vertical table top at intervals, and the second driving sliding block is connected with the two linear guide rails in a sliding manner.

Optionally, the range sensor is a laser range finder.

In a second aspect, a 3D printing method is provided, where the above sinking type 3D printer is used, and the method includes the following steps:

step S1: adding resin liquid into the resin tank, starting a second linear driving mechanism, and moving the scraper to a specified distance Y above the liquid level of the resin liquid;

step S2: setting the thickness of a printing layer as a, starting a first linear driving mechanism, descending a printing platform by a specified distance X, immersing the printing platform in resin liquid, and then ascending by a specified distance X-a;

step S3: after the printing platform is stabilized, starting a scraper motor, and rotationally scraping redundant resin liquid exceeding the printing layer thickness a on the printing platform by the scraper;

step S4: starting the optical machine, solidifying the layer thickness remained on the printing platform into a resin liquid, and carrying out a solidification reaction on the resin liquid to obtain a solidified resin layer;

step S5: after the curing of the cured resin layer is finished, the printing platform continuously moves downwards for a specified distance X, is immersed in the resin liquid and then rises for a specified distance X-a, the scraper motor is started again, and the scraper scrapes off the excess resin liquid exceeding the layer thickness a on the cured resin layer to prepare for printing of the next layer;

and step S6, repeating the step S4 and the step S5 until the 3D model printing is completed.

Alternatively, in step S1, the distance between the scraper and the liquid level of the resin liquid in the resin tank is measured in real time by the distance measuring sensor, and when the distance between the scraper and the liquid level of the resin liquid is measured by the distance measuring sensor to be the specified distance Y, the scraper stops moving.

The invention has the beneficial effects that:

according to the sunken 3D printer, printing consumables such as the release film and the spacing film are not needed to be used in the resin tank, and a printing light path does not pass through the release film, the spacing film and the resin tank glass, so that the influence of refraction on the precision is avoided, and the printing precision of the model is improved. Print the model and solidify the shaping in print platform top, do not exist and fall the board phenomenon, compare in traditional pull-up formula 3D printer, this formula of sinking 3D printer printable bigger, heavier 3D model.

According to the 3D printing method, the sunken 3D printer is used, the printing precision and the printing efficiency of the 3D model are high, the printing thickness of each layer of the model is accurately controlled, printing consumables such as the release film and the spacing film do not need to be replaced in the printing process, and the printing manufacturing cost is low.

Drawings

Fig. 1 is a schematic front structural diagram of a sunken 3D printer according to an embodiment of the invention;

fig. 2 is a schematic back structure diagram of the sunken 3D printer according to the embodiment of the invention.

In the figure:

1. a main table top; 11. a horizontal table top; 111. a resin tank; 12. a vertical table top; 121. a strip-shaped through hole;

2. a first linear drive mechanism; 21. a first screw mounting seat; 22. a first drive screw; 23. a first drive motor; 24. a first drive slider;

3. a second linear drive mechanism; 31. a second screw mounting seat; 32. a second drive screw; 33. a second drive motor; 34. a second driving slider; 35. a linear guide rail;

4. a printing platform; 41. a platform bracket; 42. a platform pallet; 43. a platform bracket connecting block; 431. a linear bearing;

5. an opto-mechanical scraper assembly; 51. an opto-mechanical mechanism; 511. an optical machine; 512. an optical machine mounting base; 52. a scraper mechanism; 521. a scraper motor; 522. a scraper shaft; 523. a scraper; 5231. and a distance measuring sensor.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar parts throughout or parts having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediary, a connection between two elements, or an interaction between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, unless otherwise expressly specified or limited, the first feature "on" or "under" the second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but with another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

As shown in fig. 1-2, the present invention provides a sunken 3D printer, which includes a main table 1, a first linear driving mechanism 2, a second linear driving mechanism 3, a printing platform 4 and an optical mechanical scraper assembly 5. The main table board 1 comprises a horizontal table board 11 and a vertical table board 12 which are vertically arranged, the horizontal table board 11 is fixedly connected with the vertical table board 12, a resin groove 111 is arranged on the horizontal table board 11, and the resin groove 111 is used for containing resin liquid. The first linear driving mechanism 2 is installed at one end, close to the horizontal table top 11, of the vertical table top 12, a first output end of the first linear driving mechanism 2 can move upwards or downwards along the vertical direction, and the printing platform 4 is fixedly connected with the first output end and moves upwards or downwards along with the first output end. The second linear driving mechanism 3 is installed at the other end of the vertical table top 12 far away from the horizontal table top 11, and the second output end of the second linear driving mechanism 3 can move upwards or downwards along the vertical direction. The opto-mechanical scraper assembly 5 is placed above the printing platform 4, the opto-mechanical scraper assembly 5 comprising an opto-mechanical mechanism 51 and a scraper mechanism 52. The optical-mechanical mechanism 51 includes an optical-mechanical 511 and an optical-mechanical mounting base 512, which are fixedly connected, and the optical-mechanical mounting base 512 is fixedly connected with the second output end and moves up or down along with the second output end. The scraper mechanism 52 comprises a scraper motor 521, a scraper shaft 522 and a scraper 523, the scraper motor 521 is fixedly connected with the optical machine mounting base 512, one end of the scraper shaft 522 is fixedly connected with the output end of the scraper motor 521, the other end of the scraper shaft 522 is fixedly connected with the scraper 523, a distance measuring sensor 5231 is arranged on the scraper 523, and the scraper motor 521 can drive the scraper 523 to move in a fan shape.

During printing, resin liquid is injected into the resin tank 111, the distance measuring sensor 5231 measures the distance from the liquid level of the resin liquid, the second linear driving mechanism 3 drives the optical machine scraper component 5 to move up or down integrally, the scraper 523 is moved to a specified distance Y above the liquid level of the resin liquid, then the first linear driving mechanism 2 is started, the printing platform 4 is firstly lowered by the specified distance X, the printing platform 4 is soaked in the resin liquid, then the printing platform 4 is lifted by the specified distance X-a, a large amount of resin liquid is stored on the printing platform 4 at the moment, the scraper motor 521 is started to drive the scraper 523 to rotate in a fan shape, namely the scraper 523 rotates 180 degrees around the scraper shaft 522, the excess resin liquid exceeding the thickness a on the printing platform 4 is scraped, and only the resin liquid with the thickness a is kept on the printing platform 4; then, the optical machine 511 is started to project the cross-sectional view of the printing model onto the printing platform 4, so that the resin liquid on the printing platform 4 is subjected to a curing reaction, the printing of the layer is finished, when the second layer is printed, the printing platform 4 descends again by the specified distance X, the resin liquid is made to sink over the curing molding surface on the printing platform 4, then the printing platform 4 moves upwards by the specified distance X-a, the distance between the curing molding surface on the topmost layer of the printing platform 4 and the scraper 523 is a, the scraper 523 rotates to scrape the excess resin liquid exceeding the layer thickness a on the curing molding surface, and the printing operation is repeated until the 3D model is completely printed.

Optionally, the first linear drive mechanism 2 includes a first screw mounting seat 21, a first drive screw 22, a first drive motor 23, and a first drive slider 24. Two first screw rod mounting seats 21 are arranged, and the two first screw rod mounting seats 21 are arranged on the vertical table-board 12 at intervals along the same vertical direction; two ends of the first driving screw 22 are rotatably connected with the two first screw mounting seats 21; the output end of the first driving motor 23 is fixedly connected with the first driving screw 22; the first driving slider 24 is in threaded connection with the first driving screw 22, and when the first driving motor 23 is started, the first driving slider 23 serves as a first output end of the first linear driving mechanism 2 and can drive the printing platform 4 to move upwards or downwards along the vertical direction.

Optionally, the second linear driving mechanism 3 includes a second screw mounting seat 31, a second driving screw 32, a second driving motor 33 and a second driving slider 34. Two second screw rod mounting seats 31 are arranged, and the two second screw rod mounting seats 31 are arranged on the vertical table-board 12 at intervals along the same vertical direction; two ends of the second driving screw 32 are rotatably connected with the two second screw mounting seats 31; the output end of the second driving motor 33 is fixedly connected with the second driving screw 32; the second driving slider 34 is in threaded connection with the second driving screw 32, and when the second driving motor 33 is started, the second driving slider 34 serves as a second output end of the second linear driving mechanism 3, and can drive the opto-mechanical mechanism 51 and the scraper mechanism 52 to move upwards or downwards along the vertical direction.

As shown in fig. 1 and fig. 2, in this embodiment, the first linear driving mechanism 2 and the second linear driving mechanism 3 have the same structure and are both linear modules, the first linear driving mechanism 2 is used for driving the printing platform 4 to ascend and descend, and the second linear driving mechanism 3 is used for driving the optical mechanical scraper assembly 5 to ascend and descend. The first linear driving mechanism 2 and the second linear driving mechanism 3 in the embodiment adopt a motor screw driving mode, and are good in transmission performance, strong in bearing capacity and high in displacement precision. The first linear driving mechanism 2 and the second linear driving mechanism 3 may be linear modules of other driving types, or may be hydraulically driven, and the like, and are not limited to this embodiment.

Optionally, the printing platform 4 includes a platform bracket 41 and a platform supporting plate 42, the first linear driving mechanism 2 is installed on the back of the vertical table 12, two strip-shaped through holes 121 are formed in the vertical table 12, two platform brackets 41 are provided, and the two platform brackets 41 correspond to the two strip-shaped through holes 121 one by one; one end of the platform bracket 41 is fixedly connected with the platform supporting plate 42, and the other end passes through the strip-shaped through hole 121 to be fixedly connected with the first driving slider 24. As shown in fig. 1, the first linear driving mechanism 2 in this embodiment is installed on the back of the vertical table 12, one end of the platform bracket 41 is fixedly connected to the platform supporting plate 42, and the other end of the platform bracket passes through the strip-shaped through hole 121 to be fixedly connected to the first driving slider 24, so that the platform bracket 41 and the platform supporting plate 42 are driven to move up and down synchronously when the first driving slider 24 moves up and down.

Optionally, the printing platform 4 further includes a platform bracket connection block 43, and two ends of the platform bracket connection block 43 are fixedly connected to the two platform brackets 41. As shown in fig. 1, a platform bracket connecting block 43 is fixedly connected between the two platform brackets 41, so that the stability between the two platform brackets 41 is enhanced, and the structural strength is ensured.

Optionally, a linear bearing 431 is disposed on the platform bracket connection block 43, and the scraper shaft 522 is inserted through the linear bearing 431. In this embodiment, the linear bearing 431 is disposed on the platform bracket connection block 43, the linear bearing 431 is a component commonly used in the art, and the scraper shaft 522 passes through the linear bearing 431, so that the coaxiality of the scraper shaft 522 is ensured, and the scraper shaft 522 is prevented from being deviated.

Optionally, the second linear driving mechanism 3 further includes two linear guide rails 35, the two linear guide rails 35 are disposed on the vertical table 12 at intervals, and the second driving slider 34 is slidably connected to the two linear guide rails 35, so as to ensure the moving stability of the second driving slider 34.

Optionally, the distance measuring sensor 5231 in this embodiment is a laser distance meter, which is a common instrument in the art, and other distance measuring instruments may also be used, which is not limited to this embodiment.

The embodiment also provides a 3D printing method, and the sinking type 3D printer comprises the following steps:

step S1: adding the resin liquid into the resin tank 111, starting the second linear driving mechanism 3, and moving the scraper 523 to a specified distance Y above the liquid level of the resin liquid;

in this step, the distance measuring sensor 5231 measures the distance between the scraper 523 and the liquid surface of the resin liquid in the resin tank 111 in real time, and when the distance measuring sensor 5231 measures that the distance between the scraper 523 and the liquid surface of the resin liquid is a specified distance Y, the movement of the scraper 523 is stopped. It should be noted that, during the printing process, the distance between the scraper 523 and the resin liquid is always the designated distance Y, and as the resin liquid is consumed during the printing process, the liquid level of the resin liquid is lowered, and the scraper 523 moves down along with the resin liquid.

Step S2: setting the thickness of a printing layer as a, starting the first linear driving mechanism 2, and lifting the printing platform 4 by a specified distance X-a after descending the specified distance X and immersing the printing platform in resin liquid;

in this step, the printing platform 4 is lowered by a specified distance X, so that the printing platform 4 is immersed in the resin liquid, and then the printing platform 4 is raised by a specified distance X-a, so that the layer thickness a is the thickness of the resin liquid during each 3D printing, and is set according to the printing requirements.

Step S3: after the printing platform 4 is stabilized, the scraper motor 521 is started, and the scraper 523 rotates to scrape the excess resin liquid exceeding the printing layer thickness a on the printing platform 4;

in this step, after the printing platform 4 is stabilized, the scraper motor 521 starts to drive the scraper 523 to work, and the excess resin liquid above the printing platform 4, which exceeds the printing layer thickness a, is scraped off, so that only the resin liquid with the thickness a remains on the printing platform 4. Specifically, the scraper motor 521 drives the scraper 523 to rotate in a fan-shaped manner, the scraper 523 rotates 180 degrees around the scraper shaft 522, and excess resin liquid exceeding the printing layer thickness a on the printing platform 4 is scraped off, so that only the resin liquid with the thickness a is left on the printing platform 4.

Step S4: starting the optical machine 511, wherein the thickness of the layer left on the curing printing platform 4 is a resin liquid, and the resin liquid is subjected to a curing reaction to become a cured resin layer;

in this step, the optical machine 511 projects the cross-sectional view of the printing model onto the printing platform 4, so that the resin liquid on the printing platform 4 undergoes a curing reaction.

Step S5: after the cured resin layer is cured, the printing platform 4 continuously moves downwards for a specified distance X, is immersed in the resin liquid, then rises for a specified distance X-a, the scraper motor 521 is started again, and the scraper 523 scrapes off the excess resin liquid exceeding the layer thickness a on the cured resin layer to prepare for next-layer printing;

in this step, after the resin layer on the printing platform 4 is cured, the printing platform 4 is moved downward by a designated distance X by the first linear driving mechanism 2, so that the cured resin layer on the printing platform 4 is soaked in the resin liquid, after the soaking, the printing platform 4 is raised by a designated distance X-a, the scraper 523 is started to rotate to scrape off the excess resin liquid exceeding the layer thickness a on the cured resin layer, so that only the resin liquid with the layer thickness a is left on the cured resin layer of the printing platform 4, and the next 3D printing with the layer thickness a is prepared.

In this step, steps S4 and S5 are repeatedly executed until the 3D model printing is completed, and the 3D model printing completed printing platform 4 ascends. The printed 3D model is raised above the level of the resin liquid and the 3D model is subsequently removed.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. The utility model provides a formula of sinking 3D printer which characterized in that includes:

the table comprises a main table top (1), wherein the main table top (1) comprises a horizontal table top (11) and a vertical table top (12) which are vertically arranged, and a resin groove (111) is formed in the horizontal table top (11);

the first linear driving mechanism (2), the first linear driving mechanism (2) is installed at one end of the vertical table top (12) close to the horizontal table top (11), and a first output end of the first linear driving mechanism (2) can move upwards or downwards along the vertical direction;

the second linear driving mechanism (3), the second linear driving mechanism (3) is installed at the other end, far away from the horizontal table top (11), of the vertical table top (12), and a second output end of the second linear driving mechanism (3) can move upwards or downwards along the vertical direction;

the printing platform (4) is fixedly connected with the first output end, and moves upwards or downwards along with the first output end;

bare engine scraper subassembly (5), bare engine scraper subassembly (5) are arranged in print platform (4) top, bare engine scraper subassembly (5) include:

the optical-mechanical mechanism (51) comprises an optical machine (511) and an optical-mechanical mounting seat (512) which are fixedly connected, and the optical-mechanical mounting seat (512) is fixedly connected with the second output end and moves upwards or downwards along with the second output end;

scraper mechanism (52), scraper mechanism (52) include scraper motor (521), scrape pivot (522) and scraper (523), scraper motor (521) with ray apparatus mount pad (512) fixed connection, scrape the one end of pivot (522) with the output fixed connection of scraper motor (521), scrape the other end of pivot (522) with scraper (523) fixed connection, be provided with range finding sensor (5231) on scraper (523), scraper motor (521) can drive fan-shaped motion is done in scraper (523).

2. The sink 3D printer according to claim 1, wherein the first linear drive mechanism (2) comprises:

two first screw rod mounting seats (21) are arranged, and the two first screw rod mounting seats (21) are arranged on the vertical table board (12) at intervals along the same vertical direction;

the two ends of the first driving screw (22) are rotatably connected with the two first screw mounting seats (21);

the output end of the first driving motor (23) is fixedly connected with the first driving screw rod (22);

the first driving sliding block (24) is in threaded connection with the first driving screw rod (22), and when the first driving motor (23) is started, the first driving sliding block (23) serves as the first output end of the first linear driving mechanism (2) and can drive the printing platform (4) to move upwards or downwards along the vertical direction.

3. The sinking type 3D printer according to claim 2, wherein the printing platform (4) comprises a platform bracket (41) and a platform supporting plate (42), the first linear driving mechanism (2) is installed on the back of the vertical table top (12), two strip-shaped through holes (121) are formed in the vertical table top (12), two platform brackets (41) are arranged, and the two platform brackets (41) correspond to the two strip-shaped through holes (121) one by one; one end of the platform bracket (41) is fixedly connected with the platform supporting plate (42), and the other end of the platform bracket passes through the strip-shaped through hole (121) and is fixedly connected with the first driving slider (24).

4. The sink 3D printer according to claim 3, wherein the printing platform (4) further comprises a platform bracket connecting block (43), and two ends of the platform bracket connecting block (43) are fixedly connected with the two platform brackets (41).

5. The sink type 3D printer according to claim 4, wherein a linear bearing (431) is provided on the platform bracket connection block (43), and the scraper shaft (522) is inserted through the linear bearing (431).

6. The sink 3D printer according to claim 1, wherein the second linear drive mechanism (3) comprises:

two second screw mounting seats (31) are arranged, and the two second screw mounting seats (31) are arranged on the vertical table top (12) at intervals along the same vertical direction;

the two ends of the second driving screw (32) are rotatably connected with the two second screw mounting seats (31);

the output end of the second driving motor (33) is fixedly connected with the second driving screw (32);

and the second driving sliding block (34), the second driving sliding block (34) is in threaded connection with the second driving screw (32), and when the second driving motor (33) is started, the second driving sliding block (34) is used as the second output end of the second linear driving mechanism (3) and can drive the optical mechanical mechanism (51) and the scraper mechanism (52) to move upwards or downwards along the vertical direction.

7. The sink type 3D printer according to claim 6, wherein the second linear driving mechanism (3) further comprises two linear guide rails (35), the two linear guide rails (35) are arranged on the vertical table top (12) at intervals, and the second driving slider (34) is slidably connected with the two linear guide rails (35).

8. The sink 3D printer according to any one of claims 1 to 7, wherein the distance measuring sensor (5231) is a laser distance meter.

9. A 3D printing method using the sink type 3D printer according to any one of claims 1 to 8, comprising the steps of:

step S1: adding resin liquid into the resin tank (111), starting the second linear driving mechanism (3), and moving the scraper (523) to a specified distance Y above the liquid level of the resin liquid;

step S2: setting the thickness of a printing layer as a, starting a first linear driving mechanism (2), and lifting a printing platform (4) by a specified distance X-a after descending by a specified distance X and immersing in resin liquid;

step S3: after the printing platform (4) is stabilized, a scraper motor (521) is started, and the scraper (523) rotates to scrape the excess resin liquid exceeding the thickness a of the printing layer on the printing platform (4);

step S4: starting the optical machine (511), curing the layer thickness remained on the printing platform (4) to be a resin liquid, and carrying out a curing reaction on the resin liquid to obtain a cured resin layer;

step S5: after the solidified resin layer is solidified, the printing platform (4) continuously moves downwards for a specified distance X, is immersed in the resin liquid, then rises for a specified distance X-a, the scraper motor (521) is started again, and the scraper (523) scrapes off the excess resin liquid exceeding the layer thickness a on the solidified resin layer to prepare for next-layer printing;

10. The 3D printing method according to claim 9, wherein in step S1, a liquid level distance between the blade (523) and the resin liquid in the resin tank (111) is measured in real time by the distance measuring sensor (5231), and when the distance measuring sensor (5231) measures that the liquid level distance between the blade (523) and the resin liquid is the specified distance Y, the blade (523) stops moving.